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US7032723B2 - Brake assembly with tuned mass damper - Google Patents

Brake assembly with tuned mass damper Download PDF

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Publication number
US7032723B2
US7032723B2 US10/065,471 US6547102A US7032723B2 US 7032723 B2 US7032723 B2 US 7032723B2 US 6547102 A US6547102 A US 6547102A US 7032723 B2 US7032723 B2 US 7032723B2
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Prior art keywords
hole
backplate
mass damper
tuned mass
spring member
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Expired - Fee Related, expires
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US10/065,471
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US20040074712A1 (en
Inventor
Ronald Louis Quaglia
James Leroy Swayze
Fang Chen
Yitzong Chern
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Ford Global Technologies LLC
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Ford Global Technologies LLC
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Priority to US10/065,471 priority Critical patent/US7032723B2/en
Assigned to FORD GLOBAL TECHNOLOGIES, INC. reassignment FORD GLOBAL TECHNOLOGIES, INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FORD MOTOR COMPANY
Assigned to FORD MOTOR COMPANY reassignment FORD MOTOR COMPANY ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: CHEN, FANG, CHERN, YITZONG, QUAGLIA, RONALD LOUIS, SWAYZE, JAMES LEROY
Assigned to FORD GLOBAL TECHNOLOGIES, LLC reassignment FORD GLOBAL TECHNOLOGIES, LLC MERGER (SEE DOCUMENT FOR DETAILS). Assignors: FORD GLOBAL TECHNOLOGIES, INC.
Publication of US20040074712A1 publication Critical patent/US20040074712A1/en
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16DCOUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00Parts or details
    • F16D65/02Braking members; Mounting thereof
    • F16D65/04Bands, shoes or pads; Pivots or supporting members therefor
    • F16D65/092Bands, shoes or pads; Pivots or supporting members therefor for axially-engaging brakes, e.g. disc brakes
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16DCOUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00Parts or details
    • F16D65/0006Noise or vibration control
    • F16D65/0018Dynamic vibration dampers, e.g. mass-spring systems
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16DCOUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00Parts or details
    • F16D65/02Braking members; Mounting thereof
    • F16D65/04Bands, shoes or pads; Pivots or supporting members therefor
    • F16D65/092Bands, shoes or pads; Pivots or supporting members therefor for axially-engaging brakes, e.g. disc brakes
    • F16D65/095Pivots or supporting members therefor
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16FSPRINGS; SHOCK-ABSORBERS; MEANS FOR DAMPING VIBRATION
    • F16F7/00Vibration-dampers; Shock-absorbers
    • F16F7/10Vibration-dampers; Shock-absorbers using inertia effect
    • F16F7/104Vibration-dampers; Shock-absorbers using inertia effect the inertia member being resiliently mounted

Definitions

  • the present invention relates to a brake assembly with noise damping and, more particularly, to a brake assembly including a tuned mass damper located inside of a hole formed in a brake component such as a backplate.
  • a rotor rotates with the axle of a wheel to be braked and two friction pad structures are disposed on opposite sides of the rotor.
  • Each friction pad structure comprises a brake pad mounted to a backplate, usually made of steel.
  • the friction pad structures are moved inwardly, toward one another, under the force applied by a hydraulically-actuated piston and related caliper fingers of a caliper mounting structure. When the hydraulic force is released, the pad structures are moved outwardly, away from one another, by return springs.
  • the present invention provides an improved apparatus for sound-dampening brake squeal noise by providing a brake component having a tuned mass damper located within a hole formed in the component.
  • the location of the hole and the weight and geometry of the tuned mass damper may be adjusted to provide effective damping for the particular frequencies that are to be eliminated in the brake system. Locating the tuned mass damper inside of a hole in the component has packaging and manufacturing advantages, and results in a tuned mass damper that is less susceptible to damage when in use.
  • the brake component is a backplate attached to a brake pad that applies braking force to a disk brake rotor.
  • the hole is blind and a thinned section of the backplate forms a bottom of the hole.
  • the tuned mass damper may be attached directly to the bottom such that deflection of the bottom permits the vibration damping mass to oscillate relative to the backplate.
  • the vibration damping mass may be attached to the bottom by a column, and deflection of the column permits the vibration damping mass to oscillate relative to the backplate.
  • the vibration damping mass is attached to a side wall of the hole by a beam, and deflection of the beam permits the vibration damping mass to oscillate relative to the backplate.
  • the tuned mass damper is a module adapted for insertion into the hole in the brake backplate. Contact between the module and inner surfaces of the hole transfers mechanical vibration of the backplate to the tuned mass damper.
  • FIG. 1 is an exploded perspective view of a brake assembly in accordance with a first embodiment of the invention
  • FIG. 2 is a cross-sectional view taken along line 2 — 2 of FIG. 1 showing a first embodiment of the invention
  • FIG. 3 is a cross-sectional view similar to FIG. 2 showing a second embodiment of the invention
  • FIG. 4 is a cross-sectional view showing a third embodiment of the invention.
  • FIG. 5 is a cross-sectional view showing a fourth embodiment of the invention.
  • FIG. 6 is a perspective cut-away view of a tuned mass damper module.
  • FIG. 1 is an exploded, isometric view of a disc brake apparatus indicated generally by the reference numeral 11 .
  • the disc brake apparatus 11 includes a rotatable rotor 13 that rotates with the axle of a wheel to be braked.
  • the disc brake apparatus 11 also includes two braking components 15 .
  • Each braking component 15 comprises a backplate 17 , preferably made of steel, and a brake pad 19 mounted on the rotor side of the backplate.
  • the two backplates 17 are suspended in a conventional caliper mounting structure (not shown) by, for example, rods that extend through openings 21 in the upper corners of the backplates 17 .
  • a caliper mounting permits the backplates to move axially on the support rods.
  • the plates are moved inwardly toward one another under forces supplied by a hydraulically actuated piston 23 and the related caliper fingers 24 .
  • the piston 23 and fingers 24 press the backplates inwardly, the inner surfaces of the brake pads 19 are engaged in frictional, braking contact with the rotor 13 .
  • a relatively high pitched and undesired brake squeal noise can be produced during such braking contact.
  • the brake squeal noise is of a relatively high frequency, and is produced by vibration of the braking component 15 during braking actuation.
  • the present invention is primarily intended to minimize or eliminate vibrations in the frequency range of approximately 1.4–16 kHz.
  • holes 26 are formed in the backplates 17 and are used to mount tuned mass dampers 28 .
  • at least one hole 26 and associated tuned mass damper 28 is provided on each of the backplates 17 .
  • the following descriptions will deal with a single hole 26 and tuned mass damper 28 , but it is to be understood that any number of holes and tuned mass dampers may be provided as necessary to achieve the desired amount of vibration and noise reduction.
  • the hole 26 and tuned mass damper 28 are preferably located at or near the anti-node point of the operational deflection shape of the backplate 17 .
  • the operational deflection shape is the shape assumed by the backplate 17 as it deforms from its generally flat, non-excited condition due to the vibrations it experiences under normal operational conditions.
  • the points and/or areas of maximum displacement from the at-rest condition are known as anti-nodes.
  • the holes 26 may be located such that they are partially or completely covered by the brake pads 19 when the pads are mounted to the backplates 17 .
  • the hole 26 is blind, with a thinned section of the backplate 17 forming a bottom 30 of the hole.
  • the hole 26 may be formed by any appropriate manufacturing method.
  • the tuned mass damper 28 comprises a vibration damping mass 32 in the form of a small block of material such as steel and is attached directly to the hole bottom 30 by any appropriate method such as adhesive, heat or friction welding, etc.
  • the hole bottom 30 serves as a spring member, deflecting when the backplate 17 is subjected to vibration so that the vibration damping mass 32 oscillates relative to the component.
  • the mechanical properties of the tuned mass damper 28 are such that the most common and/or most undesirable vibration frequencies experienced by the backplate 17 excite the tuned mass damper, causing it to cancel all or part of the undesirable vibration.
  • the vibration damping mass 132 is attached to the hole bottom 30 by an elastic beam 134 .
  • the hole bottom 30 may be thin enough such that the beam 134 and the hole bottom 30 together serve as a spring member permitting the vibration damping mass 132 to oscillate relative to the backplate 17 to cancel the unwanted vibrations.
  • the hole bottom 30 may be so thick relative to the thickness of the beam 134 that the bottom 30 does not contribute significantly to the spring constant of the vibration mass damper.
  • the vibration damping mass 232 is attached to an inner surface of the hole 26 by a beam 234 .
  • the beam 234 serves as a spring member permitting the vibration damping mass 232 to oscillate relative to the backplate 17 to cancel the unwanted vibrations.
  • the hole 26 may be blind, as shown in FIG. 4 , or it may be a through hole.
  • the tuned mass damper takes the form of a separate module 336 that fits into a hole 26 formed in the backplate 17 .
  • the hole 26 may be blind or it may be a through hole.
  • the module 336 is preferably generally cylindrical (but may be of any shape as long as it fits securely inside of the hole) and comprises a casing 338 preferably formed from thin steel.
  • the casing 338 may be completely enclosed or may have one or both ends open and is press fit into the hole 26 so that there is firm contact between the inner surface of the hole 26 and the outer surface of the casing 338 .
  • An elastic beam 334 is attached to an inner surface of the casing 338 , either to one of the ends as shown or to the curved side portion.
  • a vibration damping mass 332 is attached to the beam 334 , and the beam serves as a spring member permitting the vibration damping mass 332 to oscillate relative to the backplate 17 to cancel the unwanted vibrations.

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Braking Arrangements (AREA)

Abstract

A tuned mass damper for sound-dampening brake squeal noise is located within a hole formed in a brake component such as a backplate supporting a brake pad. The location of the hole and the weight and geometry of the tuned mass damper are tailored to provide effective damping for the particular frequencies that are to be eliminated in the brake system. Locating the tuned mass damper inside of a hole in the component has packaging and manufacturing advantages, and results in a tuned mass damper that is less susceptible to damage when in use. The hole may be blind, the bottom of the hole being thin enough to serve as a spring member to which a vibration damping mass is attached. In one embodiment, the tuned mass damper is a module adapted for insertion into the hole in the brake backplate. Contact between the module and inner surfaces of the hole transfers mechanical vibration of the backplate to the tuned mass damper.

Description

BACKGROUND OF INVENTION
1. Field of the Invention
The present invention relates to a brake assembly with noise damping and, more particularly, to a brake assembly including a tuned mass damper located inside of a hole formed in a brake component such as a backplate.
2. Background of the Invention
In disc brake assemblies, a rotor rotates with the axle of a wheel to be braked and two friction pad structures are disposed on opposite sides of the rotor. Each friction pad structure comprises a brake pad mounted to a backplate, usually made of steel. The friction pad structures are moved inwardly, toward one another, under the force applied by a hydraulically-actuated piston and related caliper fingers of a caliper mounting structure. When the hydraulic force is released, the pad structures are moved outwardly, away from one another, by return springs.
When the pistons and caliper fingers press the backplates inwardly, the inner surfaces of the brake pads are engaged in frictional, braking contact with the rotor. A relatively high pitched and undesired brake squeal noise can be produced during such braking engagement of the pads on the rotor. The brake squeal noise is produced by vibration of the friction pad structures during braking actuation.
To reduce the undesired brake squeal noise, it is known to use sound-dampening shims positioned both between the hydraulically-actuated piston and the piston engaging surface of the related steel backplate, and also between the caliper fingers and the caliper contact surface of the related steel backplate. One such shim structure is shown in U.S. Pat. No. 5,518,088.
It has also been proposed to attach a sheet metal plate to the backplate, the sheet metal plate having a groove cut therethrough to form tuning fork members of varying length. A damping material is applied to the tuning fork members, and the lengths of the members vary in order to damp particular frequencies of vibrations. See U.S. Pat. No. 6,283,258, assigned to the assignee of the present application.
It is desirable to provide an improved apparatus for sound-dampening brake squeal noise in which the brake squeal noise is reduced, and a variety of brake squeal frequencies may be absorbed.
SUMMARY OF INVENTION
The present invention provides an improved apparatus for sound-dampening brake squeal noise by providing a brake component having a tuned mass damper located within a hole formed in the component. The location of the hole and the weight and geometry of the tuned mass damper may be adjusted to provide effective damping for the particular frequencies that are to be eliminated in the brake system. Locating the tuned mass damper inside of a hole in the component has packaging and manufacturing advantages, and results in a tuned mass damper that is less susceptible to damage when in use.
In the preferred embodiment of the invention, the brake component is a backplate attached to a brake pad that applies braking force to a disk brake rotor. The hole is blind and a thinned section of the backplate forms a bottom of the hole. The tuned mass damper may be attached directly to the bottom such that deflection of the bottom permits the vibration damping mass to oscillate relative to the backplate. In a second embodiment, the vibration damping mass may be attached to the bottom by a column, and deflection of the column permits the vibration damping mass to oscillate relative to the backplate.
In a third embodiment of the invention, the vibration damping mass is attached to a side wall of the hole by a beam, and deflection of the beam permits the vibration damping mass to oscillate relative to the backplate.
In a fourth embodiment of the invention, the tuned mass damper is a module adapted for insertion into the hole in the brake backplate. Contact between the module and inner surfaces of the hole transfers mechanical vibration of the backplate to the tuned mass damper.
The above object and other objects, features, and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an exploded perspective view of a brake assembly in accordance with a first embodiment of the invention;
FIG. 2 is a cross-sectional view taken along line 22 of FIG. 1 showing a first embodiment of the invention;
FIG. 3 is a cross-sectional view similar to FIG. 2 showing a second embodiment of the invention;
FIG. 4 is a cross-sectional view showing a third embodiment of the invention;
FIG. 5 is a cross-sectional view showing a fourth embodiment of the invention; and
FIG. 6 is a perspective cut-away view of a tuned mass damper module.
DETAILED DESCRIPTION
FIG. 1 is an exploded, isometric view of a disc brake apparatus indicated generally by the reference numeral 11. The disc brake apparatus 11 includes a rotatable rotor 13 that rotates with the axle of a wheel to be braked. The disc brake apparatus 11 also includes two braking components 15. Each braking component 15 comprises a backplate 17, preferably made of steel, and a brake pad 19 mounted on the rotor side of the backplate.
The two backplates 17 are suspended in a conventional caliper mounting structure (not shown) by, for example, rods that extend through openings 21 in the upper corners of the backplates 17. Such a caliper mounting permits the backplates to move axially on the support rods.
The plates are moved inwardly toward one another under forces supplied by a hydraulically actuated piston 23 and the related caliper fingers 24. When the piston 23 and fingers 24 press the backplates inwardly, the inner surfaces of the brake pads 19 are engaged in frictional, braking contact with the rotor 13.
A relatively high pitched and undesired brake squeal noise can be produced during such braking contact. The brake squeal noise is of a relatively high frequency, and is produced by vibration of the braking component 15 during braking actuation. The present invention is primarily intended to minimize or eliminate vibrations in the frequency range of approximately 1.4–16 kHz.
In order to reduce and/or eliminate the undesired brake squeal noise, holes 26 are formed in the backplates 17 and are used to mount tuned mass dampers 28. Preferably, at least one hole 26 and associated tuned mass damper 28 is provided on each of the backplates 17. The following descriptions will deal with a single hole 26 and tuned mass damper 28, but it is to be understood that any number of holes and tuned mass dampers may be provided as necessary to achieve the desired amount of vibration and noise reduction.
The hole 26 and tuned mass damper 28 are preferably located at or near the anti-node point of the operational deflection shape of the backplate 17. The operational deflection shape is the shape assumed by the backplate 17 as it deforms from its generally flat, non-excited condition due to the vibrations it experiences under normal operational conditions. The points and/or areas of maximum displacement from the at-rest condition are known as anti-nodes. The holes 26 may be located such that they are partially or completely covered by the brake pads 19 when the pads are mounted to the backplates 17.
In a first embodiment of the invention shown in FIG. 2, the hole 26 is blind, with a thinned section of the backplate 17 forming a bottom 30 of the hole. The hole 26 may be formed by any appropriate manufacturing method. The tuned mass damper 28 comprises a vibration damping mass 32 in the form of a small block of material such as steel and is attached directly to the hole bottom 30 by any appropriate method such as adhesive, heat or friction welding, etc. The hole bottom 30 serves as a spring member, deflecting when the backplate 17 is subjected to vibration so that the vibration damping mass 32 oscillates relative to the component. The mechanical properties of the tuned mass damper 28 are such that the most common and/or most undesirable vibration frequencies experienced by the backplate 17 excite the tuned mass damper, causing it to cancel all or part of the undesirable vibration.
According to a second embodiment of the invention shown in FIG. 3, the vibration damping mass 132 is attached to the hole bottom 30 by an elastic beam 134. In this embodiment, the hole bottom 30 may be thin enough such that the beam 134 and the hole bottom 30 together serve as a spring member permitting the vibration damping mass 132 to oscillate relative to the backplate 17 to cancel the unwanted vibrations. Alternatively, the hole bottom 30 may be so thick relative to the thickness of the beam 134 that the bottom 30 does not contribute significantly to the spring constant of the vibration mass damper.
According to a third embodiment of the invention shown in FIG. 4, the vibration damping mass 232 is attached to an inner surface of the hole 26 by a beam 234. In this embodiment, the beam 234 serves as a spring member permitting the vibration damping mass 232 to oscillate relative to the backplate 17 to cancel the unwanted vibrations. The hole 26 may be blind, as shown in FIG. 4, or it may be a through hole.
According to a fourth embodiment of the invention shown in FIGS. 5 and 6, the tuned mass damper takes the form of a separate module 336 that fits into a hole 26 formed in the backplate 17. The hole 26 may be blind or it may be a through hole. The module 336 is preferably generally cylindrical (but may be of any shape as long as it fits securely inside of the hole) and comprises a casing 338 preferably formed from thin steel. The casing 338 may be completely enclosed or may have one or both ends open and is press fit into the hole 26 so that there is firm contact between the inner surface of the hole 26 and the outer surface of the casing 338.
An elastic beam 334 is attached to an inner surface of the casing 338, either to one of the ends as shown or to the curved side portion. A vibration damping mass 332 is attached to the beam 334, and the beam serves as a spring member permitting the vibration damping mass 332 to oscillate relative to the backplate 17 to cancel the unwanted vibrations.
Testing has shown that a tuned mass damper according to the present invention with a vibration damping mass having a mass in the range of approximately 2–10 grams is effective to eliminate undesirable braking-related vibrations in the range of 1.4–16 kHz.
The absolute and relative dimensions of the backplates 17, holes 26, vibration damping masses 32, 132, 232, 332, beams 34, 134, 234, 334, and other components of the invention shown in the drawings are for illustrative purposes only, and are not necessarily accurate depictions of the components as they would be employed in a braking system. In a braking system application, such dimensions are established as necessary to tune the vibration characteristics of the overall brake system and eliminate or minimize unwanted noise.
While the best modes for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims.

Claims (12)

1. A backplate for mounting a brake pad of a vehicle disk brake, the backplate having at least one hole formed therein and a tuned mass damper having a mass disposed within the hole for damping vibrations associated with the operation of the vehicle disk brake and an air gap disposed between at least one surface of the tuned mass damper and the hole.
2. The apparatus according to claim 1 wherein the hole is blind, a thinned section of the backplate forming a bottom of the hole, and the tuned mass damper comprises the bottom of the hole and a mass attached directly to the bottom such that deflection of the bottom permits the tuned mass damper to oscillate relative to the backplate.
3. The apparatus according to claim 1 wherein the hole is blind, a thinned section of the backplate forming a bottom of the hole, and the tuned mass damper comprises a spring member attached to the bottom and a mass attached to the spring member, deflection of the spring member permitting the tuned mass damper to oscillate relative to the backplate.
4. The apparatus according to claim 1 wherein the tuned mass damper comprises a spring member attached to a side wall of the hole and a mass attached to the spring member, deflection of the spring member permitting the tuned mass damper to oscillate relative to the backplate.
5. The apparatus according to claim 1 wherein the tuned mass damper comprises:
a casing adapted to be inserted into the hole such that an outer surface of the casing contacts an inner surface of the hole firmly to transfer mechanical vibration between the backplate and the casing;
a spring member projecting from an inner surface of the casing; and
a mass attached to the spring member.
6. The apparatus according to claim 1 wherein the hole is located at an anti-node area of an operational deflection shape.
7. A brake assembly comprising:
a brake pad operative to apply a braking force to a brake rotor, said brake pad being subject to vibration during braking;
a backplate attached to the brake pad, said backplate having a hole formed therein; and
a tuned mass damper having a mass disposed within the hole in the backplate and attached to the backplate for damping vibrations associated with operation of the brake assembly;
wherein an air gap is disposed between at least one surface of the tuned mass damper and the hole.
8. The apparatus according to claim 7 wherein the hole is blind, a thinned section of the backplate forming a bottom of the hole, and the tuned mass damper comprises the bottom of the hole and a mass attached directly to the bottom such that deflection of the bottom permits the tuned mass damper to oscillate relative to the backplate.
9. The apparatus according to claim 7 wherein the hole is blind, a thinned section of the backplate forming a bottom of the hole, and the tuned mass damper comprises a spring member attached to the bottom and a mass attached to the spring member, deflection of the spring member permitting the tuned mass damper to oscillate relative to the backplate.
10. The apparatus according to claim 7 wherein the tuned mass damper comprises a spring member attached to a side wall of the hole and a mass attached to the spring member, deflection of the spring member permitting the tuned mass damper to oscillate relative to the backplate.
11. The apparatus according to claim 7 wherein the tuned mass damper comprises:
a casing adapted to be inserted into the hole such that an outer surface of the casing contacts an inner surface of the hole firmly to transfer mechanical vibration between the backplate and the casing;
a spring member projecting from an inner surface of the casing; and
a mass attached to the spring member.
12. The apparatus according to claim 7 wherein the hole is located at an anti-node area of an operational deflection shape assumed by the backplate during application of the brakes.
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Cited By (31)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060266599A1 (en) * 2005-05-26 2006-11-30 Eric Denys Control of brake noise by tuned mass dampers
US20070045063A1 (en) * 2005-08-31 2007-03-01 Akebono Brake Industry Co., Ltd. Disc brake pad
US20090255766A1 (en) * 2008-04-15 2009-10-15 Material Sciences Corporation Shim structure for brake squeal attenuation
US20100065390A1 (en) * 2008-09-18 2010-03-18 Honeywell International Inc. Tuned mass dampers and vibration isolation apparatus
US20100252376A1 (en) * 2009-04-02 2010-10-07 Ford Global Technologies Llc Vehicle Braking Assembly
US20120024643A1 (en) * 2007-06-27 2012-02-02 Freni Brembo S.P.A. Pad for Disc Brakes
US20140231195A1 (en) * 2013-02-15 2014-08-21 GM Global Technology Operations LLC Tuned vibration damped device
US20150107946A1 (en) * 2013-10-21 2015-04-23 Honeywell International Inc. Carrier body for a brake lining of a disk brake with a damper mass for modifying the vibration
US9175733B2 (en) 2009-04-02 2015-11-03 Ford Global Technologies, Llc Transmission clutch assemblies with squawk reduction techniques
US20160017943A1 (en) * 2012-05-30 2016-01-21 Tmd Friction Services Gmbh Drum brake shoe
US20160281805A1 (en) * 2013-11-21 2016-09-29 Continental Teves Ag & Co. Ohg Friction lining arrangement for a disk brake
US10814690B1 (en) 2017-04-18 2020-10-27 Apple Inc. Active suspension system with energy storage device
US10899340B1 (en) 2017-06-21 2021-01-26 Apple Inc. Vehicle with automated subsystems
US10906370B1 (en) 2017-09-15 2021-02-02 Apple Inc. Active suspension system
US10960723B1 (en) 2017-09-26 2021-03-30 Apple Inc. Wheel-mounted suspension actuators
US11046143B1 (en) 2015-03-18 2021-06-29 Apple Inc. Fully-actuated suspension system
US11124035B1 (en) 2017-09-25 2021-09-21 Apple Inc. Multi-stage active suspension actuator
US11173766B1 (en) 2017-09-07 2021-11-16 Apple Inc. Suspension system with locking structure
US11179991B1 (en) 2019-09-23 2021-11-23 Apple Inc. Suspension systems
US11285773B1 (en) 2018-09-12 2022-03-29 Apple Inc. Control system
US11345209B1 (en) 2019-06-03 2022-05-31 Apple Inc. Suspension systems
US11358431B2 (en) 2017-05-08 2022-06-14 Apple Inc. Active suspension system
US11486460B2 (en) 2019-08-27 2022-11-01 Deere & Company Work vehicle with tuned mass dampers
US11634167B1 (en) 2018-09-14 2023-04-25 Apple Inc. Transmitting axial and rotational movement to a hub
US11707961B1 (en) 2020-04-28 2023-07-25 Apple Inc. Actuator with reinforcing structure for torsion resistance
US11828339B1 (en) 2020-07-07 2023-11-28 Apple Inc. Vibration control system
US11938922B1 (en) 2019-09-23 2024-03-26 Apple Inc. Motion control system
US20240141967A1 (en) * 2022-11-02 2024-05-02 Siemens Energy Global GmbH & Co. KG Electrically isolating tuned mass damper
US12017498B2 (en) 2021-06-07 2024-06-25 Apple Inc. Mass damper system
US12168375B1 (en) 2023-01-26 2024-12-17 Apple Inc. Motion control system
US12251973B2 (en) 2022-06-10 2025-03-18 Apple Inc. Vibration absorber

Families Citing this family (38)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU2000268640B2 (en) * 2000-08-07 2005-11-17 Freni Brembo S.P.A. Brake pad for disk brake
US7694460B2 (en) * 2004-07-16 2010-04-13 Agc Automotive Americas R & D, Inc. Tuned window sash
US7937819B2 (en) * 2005-09-19 2011-05-10 GM Global Technology Operations LLC Method of manufacturing a friction damped disc brake rotor
US7644750B2 (en) * 2005-09-20 2010-01-12 Gm Global Technology Operations, Inc. Method of casting components with inserts for noise reduction
US7975750B2 (en) * 2004-10-08 2011-07-12 GM Global Technology Operations LLC Coulomb friction damped disc brake rotors
US8245758B2 (en) * 2006-10-30 2012-08-21 GM Global Technology Operations LLC Coulomb damped disc brake rotor and method of manufacturing
US8163399B2 (en) * 2004-10-08 2012-04-24 GM Global Technology Operations LLC Damped products and methods of making and using the same
US7775332B2 (en) * 2005-09-15 2010-08-17 Gm Global Technology Operations, Inc. Bi-metal disc brake rotor and method of manufacturing
US7594568B2 (en) 2005-11-30 2009-09-29 Gm Global Technology Operations, Inc. Rotor assembly and method
US9174274B2 (en) 2006-05-25 2015-11-03 GM Global Technology Operations LLC Low mass multi-piece sound dampened article
US20090020383A1 (en) * 2006-06-27 2009-01-22 Gm Global Technology Operations, Inc. Damped part
US8056233B2 (en) 2006-06-27 2011-11-15 GM Global Technology Operations LLC Method of manufacturing an automotive component member
US20100122880A1 (en) * 2008-11-17 2010-05-20 Gm Global Technology Operations, Inc. Surface configurations for damping inserts
US9527132B2 (en) 2007-07-20 2016-12-27 GM Global Technology Operations LLC Damped part with insert
US7950441B2 (en) 2007-07-20 2011-05-31 GM Global Technology Operations LLC Method of casting damped part with insert
US9534651B2 (en) * 2007-07-20 2017-01-03 GM Global Technology Operations LLC Method of manufacturing a damped part
US8758902B2 (en) * 2007-07-20 2014-06-24 GM Global Technology Operations LLC Damped product with an insert having a layer including graphite thereon and methods of making and using the same
US7823763B2 (en) 2007-08-01 2010-11-02 Gm Global Technology Operations, Inc. Friction welding method and products made using the same
US7938378B2 (en) * 2007-08-01 2011-05-10 GM Global Technology Operations LLC Damped product with insert and method of making the same
US20090035598A1 (en) * 2007-08-03 2009-02-05 Gm Global Technology Operations, Inc. Product with metallic foam and method of manufacturing the same
US8118079B2 (en) * 2007-08-17 2012-02-21 GM Global Technology Operations LLC Casting noise-damped, vented brake rotors with embedded inserts
US8020300B2 (en) 2007-08-31 2011-09-20 GM Global Technology Operations LLC Cast-in-place torsion joint
US8210232B2 (en) 2007-09-20 2012-07-03 GM Global Technology Operations LLC Lightweight brake rotor and components with composite materials
US7836938B2 (en) * 2007-09-24 2010-11-23 Gm Global Technology Operations, Inc. Insert with tabs and damped products and methods of making the same
US8028739B2 (en) * 2007-10-29 2011-10-04 GM Global Technology Operations LLC Inserts with holes for damped products and methods of making and using the same
US8091609B2 (en) * 2008-01-04 2012-01-10 GM Global Technology Operations LLC Method of forming casting with frictional damping insert
US8104162B2 (en) 2008-04-18 2012-01-31 GM Global Technology Operations LLC Insert with filler to dampen vibrating components
US20090260931A1 (en) * 2008-04-18 2009-10-22 Gm Global Technology Operations, Inc. Filler material to dampen vibrating components
US8960382B2 (en) 2008-04-18 2015-02-24 GM Global Technology Operations LLC Chamber with filler material to dampen vibrating components
US9163682B2 (en) * 2008-07-24 2015-10-20 GM Global Technology Operations LLC Friction damped brake drum
US9500242B2 (en) * 2008-12-05 2016-11-22 GM Global Technology Operations LLC Component with inlay for damping vibrations
US9127734B2 (en) * 2009-04-08 2015-09-08 GM Global Technology Operations LLC Brake rotor with intermediate portion
US20100276236A1 (en) * 2009-05-01 2010-11-04 Gm Global Technology Operations, Inc. Damped product and method of making the same
US20100282550A1 (en) * 2009-05-07 2010-11-11 Gm Global Technology Operations, Inc. Mode altering insert for vibration reduction in components
US20100294063A1 (en) * 2009-05-22 2010-11-25 Gm Global Technology Operations, Inc. Friction damped gears
US8714232B2 (en) 2010-09-20 2014-05-06 GM Global Technology Operations LLC Method of making a brake component
DE102013200228A1 (en) * 2012-01-17 2013-07-18 Ford Global Technologies, Llc Manufacturing method of transmission clutch assembly of vehicle, involves coupling several mass dampers to clutch gear to split mode of vibration for clutch gear during engagement
AU2020322310A1 (en) * 2019-07-26 2022-03-10 Faiveley Transport Amiens Railway braking system comprising brake rigging, and rail vehicle equipped with such a system

Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3198294A (en) * 1963-12-26 1965-08-03 Budd Co Brake shoe fasteners
US4241819A (en) 1978-10-05 1980-12-30 Federal-Mogul Corporation Clutch pressure plate noise reduction
US4640390A (en) * 1983-05-17 1987-02-03 Knorr-Bremse Ag Brake lining carrier for disk brakes having divided lining elements
US4691810A (en) * 1984-02-02 1987-09-08 Akebono Brake Industry Company Ltd. Disc brake with pad pressed only at ends where antinodes of vibration occur
US5096023A (en) * 1988-03-11 1992-03-17 Alfred Teves Gmbh Spot type disc brake in particular internally straddling disc brake
US5416962A (en) 1993-12-08 1995-05-23 Eagle-Picher Industries, Inc. Method of manufacture of vibration damper
US5480008A (en) * 1994-03-23 1996-01-02 Wagner Electric Corporation Brake friction pad assembly
GB2291684A (en) * 1994-07-21 1996-01-31 Rover Group A disc brake asembly
US5515952A (en) 1994-12-05 1996-05-14 Ford Motor Company Drum brake assembly including brake shoes with mass dampening
US5538104A (en) * 1993-07-26 1996-07-23 Eagle-Picher Industries Gmbh Brake pad
US5730257A (en) 1995-03-08 1998-03-24 Robert Bosch Technology Corporation Method of manufacturing a friction member
US5746292A (en) * 1994-10-28 1998-05-05 Hino Jidosha Kogyo Kabushiki Kaisha Disk brake device for reducing brake noise
US5842546A (en) * 1996-07-03 1998-12-01 Prattville Manufacturing, Inc. Split backplate for noise suppression in brake pad assemblies
US5860494A (en) * 1995-06-13 1999-01-19 Sumitomo Electric Industries, Ltd. Vibration damper for use in disk brake
US5887686A (en) 1994-09-02 1999-03-30 Hino Jidosha Kogyo Kabushiki Kaisha Drum brake having a vibration suppression sytem
US6193024B1 (en) * 1997-12-18 2001-02-27 Eagle-Picher Wolverine Gmbh Damping plate
US6283258B1 (en) * 2000-08-29 2001-09-04 Ford Global Technologies, Inc. Brake assembly with noise damping
US6349803B2 (en) * 1999-04-08 2002-02-26 Qualitee International Ltd. Partnership Shim structure for sound dampening brake squeal noise
US6427810B2 (en) * 1999-12-14 2002-08-06 Continental Teves Ag & Co., Ohg Spot-type disc brake for an automotive vehicle
US6481545B1 (en) * 2001-03-30 2002-11-19 Nichias Corporation Vibration damping shim structure

Patent Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3198294A (en) * 1963-12-26 1965-08-03 Budd Co Brake shoe fasteners
US4241819A (en) 1978-10-05 1980-12-30 Federal-Mogul Corporation Clutch pressure plate noise reduction
US4640390A (en) * 1983-05-17 1987-02-03 Knorr-Bremse Ag Brake lining carrier for disk brakes having divided lining elements
US4691810A (en) * 1984-02-02 1987-09-08 Akebono Brake Industry Company Ltd. Disc brake with pad pressed only at ends where antinodes of vibration occur
US5096023A (en) * 1988-03-11 1992-03-17 Alfred Teves Gmbh Spot type disc brake in particular internally straddling disc brake
US5538104A (en) * 1993-07-26 1996-07-23 Eagle-Picher Industries Gmbh Brake pad
US5416962A (en) 1993-12-08 1995-05-23 Eagle-Picher Industries, Inc. Method of manufacture of vibration damper
US5480008A (en) * 1994-03-23 1996-01-02 Wagner Electric Corporation Brake friction pad assembly
GB2291684A (en) * 1994-07-21 1996-01-31 Rover Group A disc brake asembly
US5887686A (en) 1994-09-02 1999-03-30 Hino Jidosha Kogyo Kabushiki Kaisha Drum brake having a vibration suppression sytem
US5746292A (en) * 1994-10-28 1998-05-05 Hino Jidosha Kogyo Kabushiki Kaisha Disk brake device for reducing brake noise
US5515952A (en) 1994-12-05 1996-05-14 Ford Motor Company Drum brake assembly including brake shoes with mass dampening
US5730257A (en) 1995-03-08 1998-03-24 Robert Bosch Technology Corporation Method of manufacturing a friction member
US5860494A (en) * 1995-06-13 1999-01-19 Sumitomo Electric Industries, Ltd. Vibration damper for use in disk brake
US5842546A (en) * 1996-07-03 1998-12-01 Prattville Manufacturing, Inc. Split backplate for noise suppression in brake pad assemblies
US6193024B1 (en) * 1997-12-18 2001-02-27 Eagle-Picher Wolverine Gmbh Damping plate
US6349803B2 (en) * 1999-04-08 2002-02-26 Qualitee International Ltd. Partnership Shim structure for sound dampening brake squeal noise
US6427810B2 (en) * 1999-12-14 2002-08-06 Continental Teves Ag & Co., Ohg Spot-type disc brake for an automotive vehicle
US6283258B1 (en) * 2000-08-29 2001-09-04 Ford Global Technologies, Inc. Brake assembly with noise damping
US6481545B1 (en) * 2001-03-30 2002-11-19 Nichias Corporation Vibration damping shim structure

Cited By (50)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060266599A1 (en) * 2005-05-26 2006-11-30 Eric Denys Control of brake noise by tuned mass dampers
US20070045063A1 (en) * 2005-08-31 2007-03-01 Akebono Brake Industry Co., Ltd. Disc brake pad
US20120024643A1 (en) * 2007-06-27 2012-02-02 Freni Brembo S.P.A. Pad for Disc Brakes
US8794397B2 (en) * 2007-06-27 2014-08-05 Freni Brembo S.P.A. Pad for disc brakes
US8191690B2 (en) 2008-04-15 2012-06-05 Material Sciences Corporation Shim structure for brake squeal attenuation
US20090255766A1 (en) * 2008-04-15 2009-10-15 Material Sciences Corporation Shim structure for brake squeal attenuation
US8261896B2 (en) 2008-09-18 2012-09-11 Honeywell International Inc. Tuned mass dampers and vibration isolation apparatus
US20100065390A1 (en) * 2008-09-18 2010-03-18 Honeywell International Inc. Tuned mass dampers and vibration isolation apparatus
US20100252376A1 (en) * 2009-04-02 2010-10-07 Ford Global Technologies Llc Vehicle Braking Assembly
US8342297B2 (en) 2009-04-02 2013-01-01 Ford Global Technologies, Llc Vehicle braking assembly with reduced squeal
US9175733B2 (en) 2009-04-02 2015-11-03 Ford Global Technologies, Llc Transmission clutch assemblies with squawk reduction techniques
US20160017943A1 (en) * 2012-05-30 2016-01-21 Tmd Friction Services Gmbh Drum brake shoe
US20140231195A1 (en) * 2013-02-15 2014-08-21 GM Global Technology Operations LLC Tuned vibration damped device
US9341221B2 (en) * 2013-10-21 2016-05-17 Honeywell International Inc. Carrier body for a brake lining of a disk brake with a damper mass for modifying the vibration
US20150107946A1 (en) * 2013-10-21 2015-04-23 Honeywell International Inc. Carrier body for a brake lining of a disk brake with a damper mass for modifying the vibration
US20160265610A1 (en) * 2013-10-21 2016-09-15 Federal-Mogul Bremsbelag Gmbh Carrier body for a brake pad of a disk brake with absorber mass for changing the vibration
US10612611B2 (en) * 2013-10-21 2020-04-07 Federal-Mogul Bremsbelag Gmbh Carrier body for a brake pad of a disk brake with absorber mass for changing the vibration
US20160281805A1 (en) * 2013-11-21 2016-09-29 Continental Teves Ag & Co. Ohg Friction lining arrangement for a disk brake
US9890823B2 (en) * 2013-11-21 2018-02-13 Coninental Teves Ag & Co. Ohg Friction lining arrangement for a disk brake
US11046143B1 (en) 2015-03-18 2021-06-29 Apple Inc. Fully-actuated suspension system
US11945279B1 (en) 2015-03-18 2024-04-02 Apple Inc. Motion control system
US10814690B1 (en) 2017-04-18 2020-10-27 Apple Inc. Active suspension system with energy storage device
US12115827B2 (en) 2017-05-08 2024-10-15 Apple Inc. Motion control system
US11358431B2 (en) 2017-05-08 2022-06-14 Apple Inc. Active suspension system
US11701942B2 (en) 2017-05-08 2023-07-18 Apple Inc. Motion control system
US10899340B1 (en) 2017-06-21 2021-01-26 Apple Inc. Vehicle with automated subsystems
US11702065B1 (en) 2017-06-21 2023-07-18 Apple Inc. Thermal management system control
US11173766B1 (en) 2017-09-07 2021-11-16 Apple Inc. Suspension system with locking structure
US11065931B1 (en) 2017-09-15 2021-07-20 Apple Inc. Active suspension system
US10906370B1 (en) 2017-09-15 2021-02-02 Apple Inc. Active suspension system
US11124035B1 (en) 2017-09-25 2021-09-21 Apple Inc. Multi-stage active suspension actuator
US12043073B1 (en) 2017-09-25 2024-07-23 Apple Inc. Multi-stage active suspension actuator
US10960723B1 (en) 2017-09-26 2021-03-30 Apple Inc. Wheel-mounted suspension actuators
US12097740B1 (en) 2018-09-12 2024-09-24 Apple Inc. Control system
US11285773B1 (en) 2018-09-12 2022-03-29 Apple Inc. Control system
US11634167B1 (en) 2018-09-14 2023-04-25 Apple Inc. Transmitting axial and rotational movement to a hub
US11345209B1 (en) 2019-06-03 2022-05-31 Apple Inc. Suspension systems
US12054028B1 (en) 2019-06-03 2024-08-06 Apple Inc. Motion control systems
US11486460B2 (en) 2019-08-27 2022-11-01 Deere & Company Work vehicle with tuned mass dampers
US11731476B1 (en) 2019-09-23 2023-08-22 Apple Inc. Motion control systems
US11179991B1 (en) 2019-09-23 2021-11-23 Apple Inc. Suspension systems
US11938922B1 (en) 2019-09-23 2024-03-26 Apple Inc. Motion control system
US12134292B1 (en) 2019-09-23 2024-11-05 Apple Inc. Motion control systems
US11707961B1 (en) 2020-04-28 2023-07-25 Apple Inc. Actuator with reinforcing structure for torsion resistance
US11828339B1 (en) 2020-07-07 2023-11-28 Apple Inc. Vibration control system
US12215747B1 (en) 2020-07-07 2025-02-04 Apple Inc. Vibration control system
US12017498B2 (en) 2021-06-07 2024-06-25 Apple Inc. Mass damper system
US12251973B2 (en) 2022-06-10 2025-03-18 Apple Inc. Vibration absorber
US20240141967A1 (en) * 2022-11-02 2024-05-02 Siemens Energy Global GmbH & Co. KG Electrically isolating tuned mass damper
US12168375B1 (en) 2023-01-26 2024-12-17 Apple Inc. Motion control system

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